# Copyright 2008 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Authentication module that mimics the behavior of Django's authentication
implementation.

Limitations:
 - all user permissions methods are not available (requires contenttypes)
"""

#from django.template import add_to_builtins

#add_to_builtins('appengine_django.auth.templatetags')

from django.contrib.auth import SESSION_KEY, BACKEND_SESSION_KEY
from models import User

def get_user(request):
    from django.contrib.auth.models import AnonymousUser
    try:
        user_id = request.session[SESSION_KEY]
        user = User.get_by_id(user_id) or AnonymousUser()
    except KeyError:
        user = AnonymousUser()
    return user
